1. Field of the Invention
The present invention relates to a laminated battery.
2. Description of the Related Art
An ordinary battery has a battery casing capable of stowing a battery element, and a sealing plate closing the battery casing. A battery of this type is formed such that a battery casing is formed of resin, and metal is laminated to an inner side of the battery casing. A battery of this type is disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2003-7256, for example.
For a battery casing formed of resin, it is considered that the battery casing needs to be formed with an increased thickness to impart strength to the battery casing. As such, the battery tends to be large in size corresponding to the increased thickness.
Under these circumstances, batteries having a battery casing formed of a laminate film have been proposed. A battery of this type is formed into a bag shape having an opening. Respective terminals of positive and negative electrodes connected to a battery element are exposed from the opening of the battery casing. An edge portion of the opening is adhered while inwardly clamping the positive and negative terminals. In this manner, the opening of the battery casing is hermetically sealed.
However, since the respective terminals are supported by the edge portion of the opening of the laminate film battery casing, the support stiffness for the respective terminals is low. If a secondary battery including a plurality of cells is constructed using, as the cells, batteries respectively having laminate film battery casings, terminals of the respective cells need to be electrically connected to each other. When the respective terminals are electrically connected to each other, it is disadvantageous if the support stiffness for the terminals is low. Further, the laminate film battery casing has to be hermetically sealed after the terminals are supported, and thus the shape of the terminal is inevitably limited to a thin foil shape. As regards freedom of design with respect to the above electrical connection of cell terminals, and regulating the electrical capacity, this construction is not preferable.